Significance The California Regional Primate Research Center (CRPRC) has served for nine years as a centralized Primate Testing Facility (PTF) for the Contraceptive Development Branch (CDB) of the National Institute of Child Health and Human Development (NICHD). The purpose of this contract is to house and maintain a colony of cynomolgus monkeys (Macaca fascicularis) as well as use them in the conduct of experiments designed to test the safety and efficacy of contraceptive agents prior to being tested in humans. The cynomolgus monkey was chosen for these studies because of its size, lack of seasonality and its similarity to humans in many aspects of reproductive function. All animals are maintained under normal CRPRC guidelines of animal care. Objectives At the present time most agents being tested are either synthetic steroids which exhibit either progestational or androgenic activities, or immunocontraceptive vaccines, which could provide safe, effective and convenient birth control for women and men, especially those in developing countries where access to medical care is limited. Results Currently there are two studies being conducted on immunocontraceptive vaccines. One of these studies is a fertility trial, in which a group of normal cycling females have been given either the immunogen or the control treatment regimen, followed by a breeding phase to measure the actual level of success for contraception. The other study involved four normal cycling females, who were immunized with a sperm peptide. By measuring the levels of antibodies to the immunogen in the animals[unreadable] respective blood, cervical mucus and vaginal wash fuids immunogenicity could be determined. Future Directions There are plans for more immunocontraceptive studies and kinetic studies in the future. KEYWORDS cynomolgus macaque, steroidal contraception, immuno-contraception